Marijuana's Memory Paradox

Content provided by:

Cannabis research is controversial

To find out if THC has a protective effect on humans, scientists could study marijuana smokers as they age. If the theory holds, such users might be expected to develop Alzheimer's disease at lower rates than non-users—although the timing and extent of use would almost certainly also matter.

Given the controversy that would likely arise if a protective effect were to be discovered, however, no one has funded the epidemiological studies that would be needed to show this.

It's even hard to get experimental research published, according to Kim Janda, Professor of Chemistry at the Scripps Research Institute in California. In 2006, he published a paper demonstrating that THC interfered with another process implicated in the pathology of Alzheimer's disease: the formation of amyloid-beta plaques and fibrils.

Janda's THC research was rejected by several big-name journals and eventually published in the journal Molecular Pharmacology; it's now one of his most frequently cited articles by fellow scientists. Unfortunately, the article was also denounced in the press by the likes of Rush Limbaugh as an example of politicized science by hidden supporters of legalization—despite the fact that Janda also works on anti-cocaine addiction vaccines.

Although Janda would like to investigate further, he currently does not have grants to enable him to do so.

Why further marijuana studies should be funded

Bill Thies, Ph.D., chief medical and scientific Officer of the Alzheimer's Association, says of Wenk's research, "The authors of the paper make the case that one way to modulate the inflammatory reaction is to activate cannabinoid receptors. I think that's perfectly reasonable basic science."

Thies notes, however, that it's a long way from basic science to a usable drug, and pleads for a rational discussion. "The issue of marijuana is highly emotional and political and the minute it's put in context of legalizing marijuana, the discussion loses all sensible aspects."

Don Abrams, M.D., chief of hematology/oncology at San Francisco General Hospital, has studied medical marijuana use in people with HIV for more than a decade. He says, "I think the safety profile of marijuana compares very favorably to many other prescribed drugs," noting that there have not been any reported overdoses, and that most research does not support a link between smoking the drug and lung cancer (which may be because marijuana users tend to not smoke nearly as much as cigarette smokers).

"Cannabis is anti-inflammatory and it is also an antioxidant, and those are two things that we seek in treating neurodegenerative disorders," he says, "It's there, it's in nature, if the research does find that it has these benefits, why not take advantage of it?"

With five million Americans currently living with Alzheimer's and no highly effective treatment or prevention method known, any promising lead—even one as politically fraught as marijuana and related synthetics—could be worth following.

More Brain & Body Columns:

Search for all Brain & Body columns

Maia Szalavitz is a journalist and author who covers the intersection between mind, brain and behavior. She is a senior fellow at Stats.org , a media watchdog organization, which investigates coverage of science and statistics. Her own experience as a former heroin and cocaine addict brings a unique perspective to her work. She's a regular contributor to Brain & Body. Her most recent book, co-written with leading child trauma expert Bruce D. Perry, M.D., Ph.D., is The Boy Who Was Raised as a Dog and Other Stories from a Child Psychiatrist's Notebook: What Traumatized Children Can Teach Us About Loss, Love and Healing (Basic, 2007).

< Previous | 1 | 2